1. Field of the Invention
The present invention relates to surface covering materials of vehicle sun visors and vehicle sun visors having such surface covering materials.
2. Description of the Related Art
Japanese Laid-Open Patent Publication No. 6-255044 teaches a surface covering material that covers an outer surface of a vehicle sun visor. The surface covering material disclosed in this publication is manufactured by laminating a poly vinyl chloride film having a thickness of 250-500 μm onto a non-woven fabric entirely impregnated with resin. According to this publication, when the sheets of the surface covering material thus manufactured have been bonded together along the outer circumference of the sun visor by a high-frequency welding process, a sufficient bonding strength can be obtained at the bonded region inasmuch as the sheets are not readily peeled off from each other at the bonded region.
In order to cover the surface of the sun visor with a surface covering material in such a manner that the surface covering material has a tension across the surface of the sun visor, the sheets of the surface covering material are cut to have a size slightly smaller than the size of the sun visor. The outer surface of the sun visor is covered with the sheets while stretching the sheets. As a result, the surface covering material of the above publication may be tensioned due to the restoring force of the resin film that has been laminated onto the back surface of the non-woven fabric layer.
However, during a long time period of use of the sun visor, the resin film laminated onto the back surface of the non-fabric layer may acquire a permanent set. As a result, the surface covering material may sag or may cause bunching along the outer surface of the sun visor.